A number of different surgical devices clamp tissue, either as their sole function, or in conjunction with one or more other functions. For example, an endocutter is a surgical tool that staples and cuts tissue to transect that tissue while leaving the cut ends hemostatic. Typically, an endocutter clamps tissue, then staples and transects the clamped tissue. The tissue may be clamped between an anvil and a staple holder of the endocutter. An endocutter is small enough in diameter for use in minimally invasive surgery, where access to a surgical site is obtained through a trocar, port, or small incision in the body. An exemplary endocutter, with true multi-fire capability, is the MICROCUTTER™ brand endocutter proposed by Cardica, Inc. of Redwood City. That device is described in, for example, U.S. Patent Application Publication No. 2009/0065552, published on Mar. 12, 2009 (the “Endocutter Document”). A linear cutter is a larger version of an endocutter, and may be used to transect portions of the gastrointestinal tract. Like an endocutter, a linear cutter also clamps tissue before stapling and transecting it.
The amount of clamping force that is exerted on tissue by a surgical instrument such as an endocutter or linear cutter depends on both the physical configuration of the surgical instrument and the thickness of the tissue to be clamped. As a result, conventional surgical instruments are designed for use with tissue having a particular range of thickness. That range may be narrow, and may be difficult for a surgeon to discern, particularly during minimally-invasive port access and/or robotic surgery.
The use of the same reference symbols in different figures indicates similar or identical items.